The invention is related to the field of photonic devices, and in particular to cavity enhanced photonic devices capable of emitting or detecting multiple wavelengths simultaneously in a single pixel.
Multispectral infrared (IR) detection has been widely employed for applications including hyperspectral imaging, IR spectroscopy, and target identification. Traditional multispectral detection technology is based on the combination of single spectral Focal Plane Arrays (FPAs) and spectral filters or spectrometers, which require bulky, high-cost mechanical scanning instruments and have a slow response. Single pixels capable of detecting multiple wavebands simultaneously enable dramatically simplified system design with superior mechanical robustness, and thus have become the focus of third generation FPA development. Recently, three-color HgCdTe (MCT) photodiodes have been demonstrated, although their spectral cross talk is still large (>10%) due to radiative coupling. A competing multi-color detector technology is quantum-well IR photodetectors (QWIPs). However, QWIP device optimization is largely limited by its low quantum efficiency (<10%). Another alternative solution, tandem detectors have limited band selection options and large cross talk due to challenges associated with material compatibility and band edge absorption. A solution which combines high quantum efficiency and low spectral cross talk is yet to be explored.